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v3.19.1

Stock-Based Compensation Plans - Restricted stock activity (Details) - USD ($) | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | May 10, 2010 | May 24, 2007
The 2007 plan |  |  |  |  |
Number Outstanding |  |  |  |  |
Balance at the beginning of the period (in shares) | 328,122 | 299,335 | 396,595 |  |
Shares granted | 270,454 | 215,603 | 136,645 |  |
Shares forfeited | (9,900) | (10,999) | (20,377) |  |
Shares vested | (170,786) | (175,817) | (213,528) |  |
Balance at the end of the period (in shares) | 417,890 | 328,122 | 299,335 |  |
Weighted Average Grant Date Fair Value |  |  |  |  |
Balance at the beginning of the period (in dollars per share) | $ 23.49 | $ 20.24 | $ 17.98 |  |
Shares granted (in dollars per share) | 33.91 | 24.89 | 21.55 |  |
Shares cancelled (in dollars per share) | 32.06 | 24.38 | 17.79 |  |
Shares vested (in dollars per share) | 22.25 | 19.61 | 17.12 |  |
Balance at the end of the period (in dollars per share) | $ 30.54 | $ 23.49 | $ 20.24 |  |
Aggregate Value |  |  |  |  |
Balance at the beginning of the period (in dollars) | $ 7,707,239 | $ 6,058,336 | $ 7,131,200 |  |
Shares granted (in dollars) | 9,172,223 | 5,365,731 | 2,944,941 |  |
Shares forfeited (in dollars) | (317,430) | (268,200) | (362,536) |  |
Shares vested (in dollars) | (3,799,213) | (3,448,628) | (3,655,269) |  |
Balance at the end of the period (in dollars) | 12,762,819 | $ 7,707,239 | $ 6,058,336 |  |
Number of shares authorized |  |  |  |  | 2,800,000
The 2007 plan | Restricted Stock |  |  |  |  |
Aggregate Value |  |  |  |  |
Balance at the end of the period (in dollars) | $ 14,500,000 |  |  |  |
Remaining average vesting period for recognition of unrecognized compensation expense | 1 year 9 months 18 days |  |  |  |
Unrecognized compensation expense (in dollars) | $ 8,700,000 |  |  |  |
Employee Stock Purchase Plan |  |  |  |  |
Weighted Average Grant Date Fair Value |  |  |  |  |
Shares granted (in dollars per share) | $ 9.42 | $ 7.39 | $ 6.35 |  |
Aggregate Value |  |  |  |  |
Shares issued | 11,132 | 11,485 | 11,014 |  |
Maximum percentage of cash compensation allowed to be deducted for the purchase of common stock by eligible employees | 10.00% |  |  |  |
Maximum number of shares to be purchased by employee in one calendar year | 1,000 |  |  |  |
Maximum amount of shares to be purchased by employee in one calendar year (in dollars) | $ 25,000 |  |  |  |
Purchase price expressed as a percentage of the market price of the common stock on the purchase date or on the date of entry | 85.00% |  |  |  |
Number of shares authorized |  |  |  | 325,000 |

X
- Definition Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition Unrecognized cost of unvested share-based awards, other than options, awarded to employees as compensation. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(3) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(3) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(1) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(1) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(i)-(ii) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(i)-(ii) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(2) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(2) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition The highest quantity of shares an employee can purchase under the plan per period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition Intrinsic value of equity-based compensation awards vested. Excludes stock and unit options. + References No definition available. + Details
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- Definition Purchase price of common stock expressed as a percentage of its fair value. + References No definition available. + Details
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- Definition The intrinsic value of nonvested awards on equity-based plans excluding option plans that were forfeited during the reporting period as calculated by applying the disclosed option pricing methodology. + References No definition available. + Details
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- Definition Represents the maximum percentage of cash compensation allowed to be deducted each pay period for the purchase of common stock by eligible employees. + References No definition available. + Details
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